Internal combustion engine



May 28, 1935. A. s. LACK I INTERNAL COMBUSTION ENGINE Filed Nov. 16,1929 2 Sheets-Sheet 1k FIGJ FIQZ

INVENTOR ERA/01.0 3. L/YCK 8% ATTORNEY May 28, 1935. A. s. LACK2,002,658

INTERNAL COMBUSTION ENGINE Filed Nov. 16, 1929 2 Sheets-Sheet 2IIIIIIIIIIIIIIIII/ v III/I14 IIIIIIII INVENTOR fiR/VOLD 5. L HCK ATTORNEY PM May 2a, 1935 INTERNAL COMBUSTION ENGINE Arnold 8. Lack, Beloit,Wis., assignor to Fairbanks, Morse I; 00., Chi

tlon of Illinois cage, 11].. a corpora- Application November 10, 1929,Serial No. 407.134 7 volume.

This invention relates to improvements in internal combustion engines,and particularly to improved cylinder scavenging means.

An object of the present invention is to provide an improved arrangementof inlet ports, in

which the walls of the ports serve to direct the flow of scavenging airwithin the cylinder, in such a manner as to insure complete and emcientremoval of the exhaust gases therefrom.

A further object is to provide simple and effective means for directinga plurality of inflowing air streams into the interior of the cylinder,so as to form resultant air streams whose inherent path of travel isprogressively away and removed from, the outgoing flow through thecylinder exhaust ports.

An additional object is an improved provision for scavenging enginecylinders, whereby a plurality of inlet fluid streams are directed tounite into a single resultant stream having directional flow differingfrom the individual inlet fluid streams. I

A still further object is to provide an improved arrangement of inletand outlet cylinder ports, particularly in those types of internalcombustion engines, in which the ports are controlled by the workingpiston, so that the inlet ports may be situated in close proximity tothe exhaust ports, and to provide improved'means for directing thebranch scavenging streams, so as to unite them into a single closelyconfined current, directioned away and removed from the cylinder exhaustports, in order to minimize interference, admixture and diffusionbetween the inand outgoing fluid streams.

Further objects and advantages will appear from the following detaileddescription of parts and the accompanying drawings, in which Fig. 1 is afragmentary longitudinal section through a working cylinder of aninternal combustion engine, to which certain of the present improvementsare applied; Fig. 2 is a section taken along the line 22 in Fig. 1;Figs. 3 and 4 are longitudinal sections, of modified forms of the portarrangement; and Fig. 5'is a section taken along the line 5-5 in Fig. 4.It will be understood that in each of Figs. 1, 3, and 4, the pistonappears at substantially its inner, or bottom dead center position, withthe inlet ports fully open.

It will, of course, be understood that the present detailed descriptionof parts and the accompanying drawings relate only to certain preferredembodiments of the invention, and that substantial changes may be madein the described arrangement andconstruction of parts without departingfrom the spirit and full intended scope of the disclosure as defined bythe appended claims.

Referring by numerals to Figs. 1 and 2 of the 5 drawings, l0 designatesa working cylinder of a two-stroke cycle internal combustion engine, inwhich operates a piston ll of any suitable type. Inlet ports I! andexhaust ports 13 are. grouped about the cylinder, and in substantially10 the same plane, transverse of the cylinder. These ports arecontrolled, by preference, by the working piston, although it, will beunderstood that any other suitable form of control may be used withoutappreciably aflecting the underly- 15 ing principles of the invention.Conduits l4 serve to cooperate with the ports l2 to supply the inlet airor fuel laden mixture into the cylinder. These conduits may be connectedto any suitable source of supply (not shown) which 20 maintains, bypreference, a uniform pressure in the supply conduits. Likewise, theexhaust ports l3 cooperate with conduits l5 to direct the burnt gasesaway from the cylinder lb. The edges of the ports l4 and I3 are normallyrelated to each 25 other, in respect to time and distance of pistontravel. A difierence in height N between the edges of the inlet andexhaust ports, is provided to permit effectively lowering the combustionpressure in the cylinder, in advance of the first 30 introduction ofscavenging air, and thereby to insure maximum time available forcomplete cylinder scavenging.

In Figs 1 and 2, the inlet ports I! are, by preference, arranged inoppositely disposed 35 groups in the cylinder wall, the exhaust oroutlet ports l3 being arranged in the cylinder wall substantially midwaybetween the groups of inlet ports and in substantially the same plane,transverse of the cylinder. In Fig. 2 the inlet'40 ports l2 are arrangedin diametrically opposite groups, although it will be quite evident thatthey may, just as well, be arranged oifset from a diameter as shown inFig. 5. As best seen in dotted lines in Fig. 2, the walls or conduits ll45 serve to direct the inflowing air currents, inwardly, in such amanner, that the individual streams from each port I! unite into asingle closely confined air current. With this arrangement the resultantstream is directioned pro- 50 gressively away and removed from, theoutlet ports l3, thereby insuring eflicient scavenging of the cylinder.In certain of the older, prevailing port arrangements, the inflowingstreams usually cooperated with the cylinder wall or piston, in order toeffect the desired directioning of the scavenging fluids. In the presentarrangement, the ports are so disposed that the which are, in turn,directioned by the meeting impact of the individual streams. It will bequite apparent that the resultant stream is given a directional effectwhich is progressively away a from the outgoing flow of exhaust gases.This directional eil'ect may be seen by reference to the dotted linesand arrows appearing not only in Figs 1 and 2, but also employed in likemanner in the subsequent figures, hereinafter described.

In constructing the cylinder I6 as shown in Fig. 3, the ports I! are, bypreference, inclined with respect to a plane transverse of the cylinder,and likewise the piston I8 may be provided with a conical top IS, theslope of which may correspond to the inclination of the ports, as wellas to the slope of the air conduits 20. According to this arrangement,the piston cooperates with the inclined ports in aiding the flow of theinlet streams. It will, however, be seen that the scavenging principleherein described does not necessitate the use of the piston and otherengine member, apart from the ports and cylinder itself, as means fordirecting the several individual or component streams. It will beunderstood that the component streams issuing from the inlet ports, donot travel in directions such that the distance between their componentparticles and the exhaust ports 2| progressively increase, but that thispath of travel is, however, inherent in the combined streams produced bythe impact, or other form of coaction between the oppositely directionedcomponent streams.

In Figs. 4 and 5 are shown a cylinder 22 providing a modified form ofthe port arrangement. In this arrangement, the piston 23 and meansintegral therewith, cooperate with the ports 24 and passages 25 toproduce and aid the directional effect of the component inlet fluidstreams. The inlet streams are directed away and partitioned off, fromthe outlet ports 26 and conduits 21, by means of a bafiie or projection28 formed on the piston top. By this provision, the pair of inflowingstreams impinge, collide, or otherwise cooperate, while in contact withthe guiding surface of the projection, to form a single, unidirectionedflow stream within the cylinder. Further, the inlet ports 24 areinclined oppositely to the inclination of the ports I! as shown in Fig.3, in order to force the inflowing air into intimate cooling contactwith the face of the piston. A further advantage may be obtained in thisarrangement, in that dual and specially separate fuel introducing means,

such as injectors 29 and 30 may be used, due to the fact that by usingthe piston projection 28, a combustion clearance 3| is formed, in whichthese injection nozzles may be disposed. Such a combustion space is,generally, of greater diameter than depth, and is therefore particularlysuitable for the application of two or more injection nozzles. Thesenozzles may be disposed with their axes either parallel or arrangedobliquely with respect to each other.

The foregoing description relating to the course of the individual orcomponent streams of inlet air, has dealt principally with the manner ofintroducing the several separate air streams,

and thereafter directing them in a manner to cause their union into oneor more resultant streams. These resultant streams are, in each case,directed upwardly or outwardly, toward the cylinder head. Aftertraversing the cylinder, the resultant stream engages the cylinder head,which serves as a transverse bame serving radially to divert the airstream, and thereafter to cause a reverse or counterflow,.toward thepiston, and exhaust ports, as well understood in the art. Thearrangement of inlet ports described in the several figures produces amean path of scavenging fluid flow, the length of which is a minimum,consistent with its making a complete circuit of the combustion space.

By the described directional flow of the scavenging air, the commixtlneof the incoming charge with the gases left in the cylinder from theprevious working cycle, is minimized. Further, by uniting the individualor component inlet streams, the larger cross-section of the combinedstream, as well as the homogeneous front, presented thereby to theexhaust gases, render the entire stream more effective in displacing theold charge from the cylinder, than would be the case if the samequantity of scavenging air, or air-fuel mixture were caused to traversethe cylinder as a plurality of smaller, individual streams. By causingthe several individual or component streams to coalesce soon afterentering the combustion space, and thereafter presenting a substantialfront to the exhaust gases remaining from the previous working cycle,contamination and admixture of the fresh charge, is minimized, andexpulsion of burnt gases rendered more complete. The changed directionof the resultant stream caused by the impact of the individual streams,is produced with least possible abruptness. Hence, the kinetic energy ofthe entire stream is substantially preserved, to obtain greaterpenetration of the more remote recesses of the cylinder. It is,therefore, possible to use lower admission pressures, which minimize thepossibility of undesired turbulence and intermixture between the inandoutflowing streams. It will be apparent that by the use of lowerpressures employed for introducing the scavenging fluid, less enginepower is consumed for this purpose, and therefore greater engine economyis obtained.

With the presently described port arrangement, the cylinder is filledalmost entirely with pure scavenging air, and a relatively completeevacuation of the exhaust gases is attained. Also, the directioning ofthe inflowing streams is such as to avoid what may be designated as ashort circuiting of the inflowing stream through the exhaust ports, andvice versa, thereby minimizing the contamination of the fuel charge bythe exhaust gases. It will be further apparent, that the described,natural flow of the inlet air through the cylinder, drives the exhaustgases out through the exhaust ports, in such a manner as effectively toeliminate dead gas pockets within the cylinder.

I claim as my invention:

1. A cylinder for an internal combustion engine, a piston adapted tooperate therein, ports formed in a cylinder wall for the intake ofscavenging fluid, exhaust ports at right angles to the intake ports, theintake ports each being disposed in aligmnent on opposite sides of thecylinder, and directed at substantially a right angle to a plane ofsymmetry. extending along the axis of the cylinder, said intake portsbeing formed to direct the opposed streams o' intake scavenging fluid toa zone of stream-convergence substantially within said plane ofsymmetry, and a baflle structure on said piston having a portionextending along said plane of symmetry.

2. In an internal combustion engine, a cylinder, a piston adapted tooperate therein, inlet ports disposed in line, substantially on oppositesides of the cylinder, and arranged to be controlled by saidpiston,.exhaust ports at right angles to the inlet ports, said inletports all being formed to deliver streams of scavenging fluid atsubstantially a right angle to a plane of symmetry extended axiallythrough the power cylinder, and at substantially a right angle to saidexhaust ports, and a baflile projecting at substantially a right angleto the working face of said piston, and formed to'maintain substantiallythe initial trends of said streams, between said ports and said plane ofsymmetry.

3. In an internal combustion engine, a cylinder, inlet and exhaustports, the exhaust ports being at right angles to the inlet ports, saidinlet ports all being arranged in opposed alignment, and directionedtocause a flow, along a common plane, of individual streams ofscavenging fluid, causing said streams to converge in a plane parallelto and extending along said exhaust ports, at a right angle to the firstnamed plane, a piston operable in the cylinder, and a baflle structurethereon, having angularly disposed stream-directing portions.

4. An internal combustion engine, a cylinder, and a piston adapted tooperate therein, inlet and exhaust ports in the cylinder wall, theexhaust ports being arranged at a right angle to the inlet ports and theports all being symmetrically arranged with respect to a plane includingthe axis of the cylinder, said ports adapted to be controlled by saidpiston, said inlet ports being disposed in opposed spaced relation anddirected to efiect a movement of each of the inlet streams along acommon plane at a right angle to the plane of symmetry, whereby toefiect a union of fluid streams from the several inlet ports atsubstantially a common point, and whereby the fluid streams from saidinlet ports are caused, after proceeding beyond said point, to traversethe combustion space within the cylinder, and a deflecting structure onthe piston having a portion substantially coincident with the said planeof symmetry.

5. In an internal combustion engine, a cylinder including inlet portsadapted to be controlled by a piston, and disposed in opposite wallportions of the cylinder, the ports being arranged symmetrically withrespect to a plane directed along the axis of the cylinder, and eachbeing of a trend to cause the individual streams therefrom to follow acommon plane, and to unite at a common point, within the plane ofsymmetry, the impingement of such streams adapted to produce a resultantunidirectional flow of scavenging fluid, in a direction along the planeof symmetry, and substantially over the length of the combustion portionof said cylinder, exhaust ports at right angles to the inlet ports, apiston operable in the cylinder, and a baffle on the piston,characterized by portions extended, respectively, across the producedaxes of the inlet and exhaust ports.

6. In an internal combustion engine, a cylinder, a piston adapted toreciprocate therein, a pair of inlet ports and an exhaust port at rightangles to the inlet ports, the ports being symmetrically disposed abouta plane extended along the cylinder axis, the inlet ports being disposedon opposite sides of the cylinder in a plane normal to the plane ofsymmetry and thereby arranged for efiecting convergence of the inletstreams, and for directing a flow of intake fluid after convergence ofsaid streams, in substantially a straight line to the head portion ofthe cylinder, and a baiile on the piston having portions extending,respectively, along and across the said plane of symmetry.

7. In an internal combustion engine, a cylinder, a piston adapted tooperate therein, a plurality of intake fluid ports and exhaust ports atright angles to the intake ports, the ports being also symmetricallydisposed with respect to a plane including the axis of the cylinder,said intake ports each being disposed substantially in a plane at aright angle to said plane of symmetry, and of a trend adapted to conductthe intake fluid in opposite directions across and in close adjacence tothe piston face, said intake ports being formed to project all of saidintake fluid toward a common point adjacent the piston and in the planeof symmetry, to eifect a resultant fluid stream proceeding from thepiston along the axis of the cylinder to the head end thereof, andbaflles on the piston, one being of a trend along said result-antstream, and a second baiile at a right angle to the flrst.

ARNOLD S. LACK.

